In a typical cellular radio system, mobile user equipment (UE) communicates via a radio access network (RAN) to a core network. User equipment (UE) comprises various types of equipment such as mobile telephones (also known as cellular or cell phones), laptops with wireless communication capability, personal digital assistants (PDAs) etc. These may be portable, hand held, pocket sized, installed in a vehicle etc. and communicate voice and/or data signals with the radio access network. They may or may not be human-operated (examples of non-human operated UEs being those for machine-type communications such as for remote monitoring or metering applications).
A radio access network covers a geographical area typically divided into a plurality of cell areas. Each cell area is served by at least one base station, which in UMTS may be referred to as a Node B. Each cell is typically identified by a unique identifier which is broadcast in the cell. The base stations communicate at radio frequencies over an air interface with the UEs within range of the base station. Several base stations may be connected to a radio network controller (RNC) which controls various activities of the base Stations. The radio Network controllers are typically connected to a core network.
UMTS is a third generation public land mobile telecommunication system. Various standardization bodies are known to publish and set standards for third generation public land mobile telecommunication systems, each in their respective areas of competence. For instance, the 3GPP (Third Generation Partnership Project) in addition to publishing and setting standards for UMTS, also publishes and sets standards for GSM (Global System for Mobile Communications); 3GPP2 (Third Generation Partnership Project 2) publishes and sets standards for CDMA (Code Division Multiple Access).
The 3GPP TS 45.008 Standard, version 10.1.0 (2011 May) describes measurements of cells of radio access technologies in sections 6.6.4 ff. The 3GPP TS 36.133 Standard, v10.3.0 (2011 June) in section 4.2.2. addresses measurements of intra-frequency E-UTRAN cells. The 3GPP TS 25.304 Standard, v10.1.0 section 5.2.6 ff describes measurements when in UMTS Idle mode. In addition 3GPP TS 25.133 Standard, v10.4.0 section 4.2 describes some performance requirements for cell reselection measurements. The specifications are referred to herein as the “Standard”, and are incorporated herein by reference.